Zhaojin Mining Industry Company (HKG:1818) said it would invest $30 million in Zijin Gold International's (HKG:2259) public offering as a cornerstone investor, according to a Hong Kong bourse filing on Friday.

Zijin Gold International earlier launched its initial public offering in Hong Kong, aiming to raise up to HK$24.98 billion from the deal.

The IPO is poised to become the second-largest listing in the Asian financial hub this year, next to Contemporary Amperex Technology or CATL (HKG:3750, SHE:300750), which raised HK$41 billion.

Allocation results are expected to be disclosed Sept. 26, ahead of the company's trading debut on the bourse on Sept. 29.